The present invention relates, in general, to display devices, and more particularly, to light emitting diode display devices.
In the past, light emitting diodes (LEDs) have been used to create images for visual displays in a variety of applications including communication and visual display devices. In order to provide a full color display, it is important to have LEDs that produce pure red, green, and blue colors that can be combined at different intensities to produce all the required colors of a full color display. Multicolor organic LEDs have even been fabricated on a single substrate in order to create a multicolor image or display. One example of such a multicolor organic LED array is given in U.S. Pat. No. 5,424,560 issued to Norman et al. on Jun. 13, 1995. One problem with prior multicolor organic LED displays is that either the red or green color is not of a appropriate wavelength to produce a full color display. For example, organic LEDs generally produce a red that has a peak at about 610 nanometers instead of the desired 650 nanometers for the color red. Consequently, displays utilizing such organic LEDs do not produce proper full color displays.
Additionally, it is very difficult to produce a gallium arsenide semiconductor LED that emits blue light with a peak around the 400 to 470 nanometers desired for the color blue.
Further, it is very difficult to produce on a single substrate semiconductor LEDs that emit blue light at the desired wavelength along with red and green light at the desired wavelengths.
Accordingly, it is desirable to have full color light emitting display that has red, blue, and green LEDs that have peaks in the desirable ranges in order to provide full color images.